A cyber-attack resilient load frequency control for two area power system using particle swarm optimized 3-degree-of-freedom–PID controller

In modern power systems, stable power distribution relies on effective control and power sources management, which is possible through integration of communication systems and Internet. As the Internet and communication introduced, it creates the risk of cyber-attacks on power grid. The attackers perform malicious actions such manipulating the data, blocking the data or creating a delay to prevent timely communication with controller or even intentionally feeding incorrect data to the controller. Cyber-attacks disrupt grid operations by manipulating control systems, causing incorrect power adjustments. This leads to frequency imbalance, which can trigger blackouts or damage equipment due to stress and overheating. To address this issue of cyber-attack and frequency imbalance, a 3-degree-of-freedom (3-DOF)–PID controller has been implemented for load frequency control (LFC) of an interconnected power system. The controller offers effective control action to make the frequency within acceptable limits by reducing the frequency oscillations and overshoot with improving response time. A particle swarm optimization (PSO) technique is applied for optimal tuning of 3-DOF-PID controller gains. In this paper, various cyber-attacks with their adverse impacts and the effect of disturbance in renewable sources on grid frequency stability have been considered. Furthermore, a comparative study has been done among genetic algorithm (GA) and PSO with conventional (PID), 2-DOF-PID, and 3-DOF-PID controllers to show the supremacy of proposed controller. The simulation work is performed on MATLAB/Simulink and the results have been validated using OPAL-RT (OP4512) real-time simulator. The PSO-3-DOF-PID control provides efficient control against the various cyber-attacks and disturbance.